v8 typed arrays: add DataView type

src/utils.h

Index: src/utils.h
diff --git a/src/utils.h b/src/utils.h
index 93cded18bcd2f9c07dc9c29ec567bbc565bb3520..46dabfdeb323643b54d2c68cf9503f0559e8e317 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -239,6 +239,46 @@ inline int StrLength(const char* string) {
 }
 
 
+template <typename T>
+inline void Swizzle(T* value) {
+  char* start = reinterpret_cast<char*>(value);
+  char* end = start + sizeof(*value) - 1;
+  while (start < end) {
+    char t = *start;
+    *start++ = *end;
+    *end-- = t;
+  }
+}
+
+
+enum Endianness {
+  kLittleEndian,  // _Not_ LITTLE_ENDIAN, clashes with endian.h.
+  kBigEndian
+};
+
+
+inline enum Endianness GetEndianness() {
+  // Constant-folded by the compiler.
+  const union {
+    uint8_t u8[2];
+    uint16_t u16;
+  } u = {
+    { 1, 0 }
+  };
+  return u.u16 == 1 ? kLittleEndian : kBigEndian;
+}
+
+
+inline bool IsLittleEndian() {
+  return GetEndianness() == kLittleEndian;
+}
+
+
+inline bool IsBigEndian() {
+  return GetEndianness() == kBigEndian;
+}
+
+
 // ----------------------------------------------------------------------------
 // BitField is a help template for encoding and decode bitfield with
 // unsigned content.